1. Field of the Invention
The present invention relates to a scanning endoscope apparatus.
2. Description of the Related Art
Conventionally, a scanning endoscope apparatus has been proposed which causes a distal end of an optical fiber guiding unpolarized light from a light source to perform scanning and receives return light from a subject with an optical fiber bundle arranged around the optical fiber to generate an image using a light intensity signal sequentially detected over time (see, for example, Japanese Patent Application Laid-Open Publication No. 2003-535659).
Furthermore, an endoscope apparatus is proposed which is for, at the time of performing observation and the like using an endoscope, observing a polarized image using polarization, for example, for diagnosis of early-stage cancer and the like, in addition to observation using unpolarized light (see, for example, Japanese Patent Application Laid-Open Publication No. 2009-213649, and Japanese Patent Application Laid-Open Publication No. 2010-104422).
In the endoscope apparatus of Japanese Patent Application Laid-Open Publication No. 2009-213649, by providing a polarization separation device and an image pickup device such as a CCD, at a distal end portion of an endoscope distal end, a polarization component of return light of light illuminating a living body can be separated.
The endoscope apparatus of Japanese Patent Application Laid-Open Publication No. 2010-104422 sequentially radiates multiple illumination lights in different polarization states to an observation site for each different wavelength spectrum by sequentially switching among respective multiple color filters and multiple illumination light polarization filters. Then, after polarizing return light from the observation site with a polarization filter section provided at a distal end portion of an endoscope in a predetermined direction, the endoscope apparatus performs image pickup with an image pickup device such as a CCD.